Acute Effects of Circuit Training and Traditional Resistance Exercise on Sclerostin in Young Adults

Pragya Sharma Ghimire

College: College of Health Professions and Human Services

Department: Health and Human Performance

Abstract:

Introduction: Evidence suggests that physical activity promotes bone health through mechanical loading and biochemical signaling between bone and muscle tissues. A class of signaling molecules called exerkines plays a crucial role in mediating bone–muscle crosstalk. Exercise provides a myriad of health benefits by modulating osteokines; however, the underlying mechanisms of the acute effects of exercise training on sclerostin (SCL) and osteopontin (OPN) are unclear. Purpose: This study compared acute serum SCL and OPN responses to circuit training (CT) and traditional resistance (TR) exercise in young healthy adults. In this randomized, repeated-measures crossover study, 6 men and 6 women completed the protocols across 4 visits. Participants performed two protocols separated by 2-week wash-out periods: 1. CT (cycle ergometer, push-up, step-ups, medicine ball twist, and front squats with kettlebell for three sets) and 2. TR exercise (3 sets 10 repetitions 80% 1RM for leg press, seated cable row, barbell bench press, kettlebell deadlifts, and dumbbell seated shoulder press). Blood samples were analyzed before exercise training (PRE), immediately post-exercise (IP), and 30 minutes post-exercise (30P) for SCL and OPN using ELISA. Results: There was a significant (p<0.01) protocol*sex* time point interaction observed for SCL levels. In males, SCL levels increased from PRE to IP under both training protocols (CT: 0.10 ± 0.02 ng/mL to 0.14 ± 0.02 ng/mL; TR: 0.20 ± 0.02 ng/mL to 0.21 ± 0.02 ng/mL). In females, SCL levels increased from PRE to IP under both training protocols (CT: 0.03 ± 0.02 ng/mL to 0.06 ± 0.02 ng/mL; TR: 0.79 ± 0.02 ng/mL to 0.12 ± 0.02 ng/mL). For OPN, we only found a significant main effect of time, with a decrease from PRE to 30P (18.84 ± 0.92 to 15.69 ± 1.32 ng/ml). Conclusions: The results suggest that acute exercise training induces transient increases in circulating SCL in both males and females, followed by a rapid decline during recovery, supporting the notion that osteokines are regulated by mechanical loading and that markers of bone’s mechanosensitive response to exercise are elevated.